It is considered Canberra's worst natural disaster, one that tragically reshaped the look and attitude of the bush capital.

On January 18, 2003, four bushfires that had been burning in Brindabella mountains for more than a week combined and roared into Canberra's south-western suburbs, destroying 500 homes and claiming four lives.

Most knew the fires were coming but almost all underestimated the scale of the firestorm and overestimated the capacity of the authorities to stop it.

It was a massive bushfire that created its own weather, with cyclone-strength winds and fire tornados. In every sense, a firestorm.

When the fires hit the suburbs, they took the public - and the authorities - almost entirely by surprise.

Four residents died in a hopeless battle to protect their homes or escape the flames.

Hundreds more people were injured - some critically. They suffered horrendous burns, smoke inhalation, broken limbs, and exhaustion.

There had been no official order to evacuate their homes.

It was, in essence, every man and woman for themselves.

Bushland tinderbox

The fires began on January 8, 2003, when a series of dry lightning storms swept over the vast expanse of Namadgi National Park, which makes up nearly two-thirds of south-west ACT.

When authorities detected the fires, they dispatched small crews into some of the most remote sections of the bush.

But the fires were hard to access and there was no real sense of official urgency.

They were subsequently criticised in an ACT Government inquiry and a long-running coronial inquest, for doing too little, too slowly.

The McLeod Inquiry concluded the fires "might have been contained had they been attacked more aggressively in the 24 or so hours after they broke out."

But the eucalypt forests had been desiccated by years of drought and once the fires took hold, they were impossible to contain.

For more than a week emergency services officials provided community and press briefings on the growing scale of the fires, but little was said publicly to suggest Canberra's suburbs might be at risk.

Key officials dared not to even think it was a possibility, until it was too late.

In the blame game that followed, NSW fire authorities claimed they had issued their ACT counterparts with clear warnings that Canberra's suburbs had been under threat.

Those warnings had never been passed on to the public.

Fires reach Canberra

On the morning of January 18, 2003, there were ominous signs in the sky.

Residents woke to the news that the fires had broken containment lines overnight and were now being fanned towards Canberra's suburbs.

In the city's western suburbs, the sight of ash and burnt leaves falling from the sky - carried tens of kilometres from the fire front to the west - was considered a novelty but little more.

Still, the official firefighting effort was centred around protecting isolated rural settlements and Canberra residents planned their Saturdays in blissful ignorance.

Many headed to the New South Wales south coast to cool down, while others prepared to enjoy another hot summer's day in the capital.

Fire authorities had hoped to stop the fires from crossing the Murrumbidgee River corridor, less than four kilometres west of the Weston Creek suburbs of Duffy, Rivett and Chapman.

As it turned out, even their worst case scenario was to prove dramatically optimistic.

The fire had blown out to a 30-kilometre front, with destructive fire weather forecast, temperatures above 40 degrees Celsius and gusty winds.

What had started as four discrete fires combined into one unstoppable blaze that roared into the suburbs.

Burning suburbs

Between 1pm and 1:30pm the fires crossed the Murrumbidgee River and only then did ACT emergency authorities seriously consider the suburbs were under threat.

From the river it was all uphill to Canberra, the conditions under which fire spreads fastest.

Fire experts later estimated the pace at 20 kilometres per hour, believed to be the fastest documented rate of spread of a forest fire.

The first public emergency warning was finally issued just after 2pm, listing Duffy, Chapman, Rivett, and Holder as areas most at risk.

Instead of urging residents to leave the area, it asked them to return to their homes and prepare for the coming fire front.

At first, a senior emergency services official resisted police efforts to declare a state of emergency, which would allow police to forcibly evacuate residents.

By 2:45pm, the fire began burning extensive pine plantations around Mount Stromlo and eventually destroyed the historic observatory telescope complex that sat at the crest of the hill.

Pine forests also surrounded the suburb of Duffy on two sides, and firefighters dispatched to Eucumbene drive on the the suburban fringe were quickly forced to retreat.

In the end, police road blocks stopped other residents from returning to join the effort.

Those road blocks remained in place many hours after the fire front had passed, but houses were still catching alight from their neighbours.

Some saw it as a case of appalling judgement to block people from the streets, and in hindsight, perhaps some of those homes could have been saved.

Dreadful toll

That afternoon, some 500 homes were destroyed across half a dozen suburbs and rural communities.

Most house losses were in the streets closest to the pine forests but it was a random game of chance.

Some homes were ignited by spot fires kilometres away, while others remained intact surrounded by scenes of utter devastation.

Thousands of residents were displaced and had to be housed at emergency evacuation centres until they could find alternative accommodation.

The four people who died in and near Duffy had been battling the fire front in vain.

One fell from the roof of his house, garden hose still in hand.

Another died lying in her bathtub surrounded by wet towels.

She had apparently misunderstood official advice to fill a bathtub to act as a water source, with tragic consequences.

The Canberra Hospital was over-run with the walking wounded, many suffering burns and smoke inhalation. The emergency department just could not cope and the worst injured were flown to Sydney for specialist treatment.

At 7pm a cool wind change saw an end to the fire emergency and the epic fight to save homes turned to one of rebuilding a shattered community.